Concealed objects detection is a challenge facing the law enforcement community today and requires more than metal detectors in the high security environment now required. There must be reliable techniques to detect and identify non-metallic objects or other threatening objects that may be concealed under clothing.
People screening for objects and explosives is an estimated $8 billion market by the year 2008 (Source: Homeland Security Research Corporation). A recent report by Research and Markets estimates the cost of screening a single person is between $4 and $5. The estimated queuing time at airport checkpoints in the U.S. is now over 20 min. During peak hours the queuing time is much larger and lines of waiting passengers snake inside and outside the airport.
It is quite clear screening people with metal detectors prior to entering secured areas is ineffective in preventing some objects from getting through. It is nearly an impossible task to achieve 100% success given the tools screeners have available today.